defensive spells

So the basic idea behind this would be magical traps. You can place runes on your map that act ask a magical defense.
Ideas would include runes that act as land mines (fire, frost, electric), or times spells to slow down units. They would cost to reset like regular traps and can be created in your spell factory.

Addition to this idea would be the posiblity that wizard units could deactivate them or not be harmed by magical attacts.

If the 2nd portion was implimented i think adding a dispell rune would be interesting. Basically any unit that uses magic would be disabled with in its rang for a few seconds, ex. witch or wizard

Would love thoughts or additions to this idea.